u.s. troops now missing in afghanistan. new details of how they were ambushed at a busy marketplace. >>> an open book. the place 500 million people are now revealing the instant secrets of their lives. >>> good evening. all eyes were on the gulf early today and whether a tropical storm would make the disastrous oil spill even worse, but we begin with the weather tonight a thousand miles to the north and east. torrential rain soaking portions of the midwest stranding residents, flooding highways and causing a dam to fail. in the east, deadly triple-digit heat and tropical humidity making this one of the worst days in the summer of record-breaking temperatures. we have two reports on the extreme weather. we start off with abc's eric horng who is outside of chicago in westchester, illinois. >> reporter: good evening, sharyn. the water here came up quickly while many were asleep. and today many streets here in westchester look just like this one. the water here has started to recede but for ma